This invention relates to concrete finishing machines for use in finishing concrete surfaces of roadways and the like, and more particularly to a concrete finishing machine having a vibrating finishing roller assembly.
Concrete finishing machines used in finishing concrete surfaces of roadways and the like, employ apparatus for vibrating the concrete to condition the surface of the concrete being finished for enhancing and improving the finished surface. One known type of concrete finishing machine includes vibrator apparatus in the form of a pan which is dragged along the surface of the concrete being finished ahead of the finishing rollers. The pan is vibrated as it is dragged forwardly along the roadway, or the like. Another concrete finishing machine, disclosed in the U.S. Pat. No. 4,320,987 of Murray A. Rowe, et al, includes a vibrating apparatus which is movable back and forth transversely over the roadway being surfaced, with the vibrating apparatus extending into the concrete being finished to condition concrete ahead of the finishing rollers. The vibrator apparatus includes generally L-shaped rod members suspended on a support frame and actuated as by an hydraulic motor to be raised and lowered relative to the roadway being finished.
In another arrangement disclosed in U.S. Pat. No. 4,068,970 to Murray A. Rowe, a concrete finishing machine includes a screen mechanism for striking-off and smoothing spread concrete. The screen mechanism is vibrated to vibrate the concrete to the proper density and best quality finish during finishing.
Although finishing processes using these known concrete vibrator apparatus improve the quality of the concrete surface finish, the extent to which these finishing processes can provide the finish desired for the concrete being worked id dependent upon the water/cement ratio. In some applications, the specifications for the concrete mix require drier concrete, and the water/cement ratio is reduced. This increases the strength of the cured concrete, but renders the concrete less workable and increasingly more difficult to finish. To finish drier specification concrete, it is desirable to additionally work the surface in a manner that moves the rock-aggregate below the surface and increases the workable fines to the surface.